Thermometer assembly with limited luminous background



Jan. 19, 1954 M. J. HILER 2,656,329

THERMOMETER ASSEMBLY WITH LIMITED LuMINous BACKGROUND Filed May 4, 195o le T #I2 ATTORNEYS Patented Jan. 19, 1954r UNITED STATES -TENT OFFICE.Y

VTHERIWOMETER, ASSEMBLY WITH LIMITED LUMINOUS BACKGROUND Application May 4, 1950, Serial No. 160,068

2 Claims. (Cl. 'Z3-376) The instant invention relates to thermometers. More particularly, it relates to thermometers which may be read either in daylight or in the dark. Still more particularly, it relates to thermometer construction allowing reading in the dark irrespective of the type of fluid within the thermometer tube. v

This is an advantage because, Vfor example, in manufacturing -plants and the like electric lights are not always positionable where theywill illuminate a thermometer, or upon power failure no light may be available to determine the course of a reaction which cannot be stopped without the loss of an entire run of material.

It is an object of the present invention to overcome the disadvantages `and limitations of the thermometer equipment currently in use.

It is also an object of this invention to provide a thermometer in which the position of the indicating column will always be observable in conjunction with a luminous background.

It is also an object of this invention to provide a thermometer which may have a luminous backing for the bulb and indicating column as a permanent part of the base or as a detachable section.

It is a further object of the present invention to provide a luminous base which will convert daylight thermometers to night reading thermometers.

Various other objects and advantages will be apparent to one skilled in the art as the following description proceeds.

Briey, the invention comprises a base upon which is disposed a luminous area as background against which to observe the thermometer bulb and stem, particularly the stem.

The thermometer liquid holding unit is positioned in front of the luminous area so as to be silhouetted thereagainst.

The use to which the thermometer is to be put determines the type of base to which the luminous area is to be applied. Where a thermometer is to have the bulb portion deposited in a thermometer well, the luminous area, Wil1 merely be on the face of a sti cardboard or metal tab positioned behind and preferably attached to that portion of the thermometer stem protruding from the well.

This tab may also carry a printed replica of the thermometer scale in non-luminous paint surrounded by luminous paint or vice versa, under either circumstances of which the scale will be readable in the dark.

If the thermometer requires a support, the support may be of .any suitable material, suchas wood or metal, to which the thermometer is secured by suitable brackets, clasps and the like. The luminous area may be painted directly on the supportV or the support may havea cardboard or metal tab which carries the luminous area positioned between the support and the thermometer.

Where the thermometer currently in use is of a construction holding the thermometer spaced from the support the cardboard or metal tab may be insertable to convert'tliese thermometers to night reading thermometers. Luminous areas are preferably of a size to give adistinct rim of material outlining the thermometer, the area behind the thermometer being painted in configurations as will be shown hereinater.

'l't has been discovered that the luminous area of these coniiguratlons make a clearly readable night thermometer. If the liquid in the clear ti'iermometer stem is Opaque and non-luminous it produces a dark column, obsouring the luminous area behind and showing a very dennite end point at the meniscus in the capillary tube.

If the liquid 1s a transparent or translucent liquid oi' relatively light color the liquid acts as though it too were luminous but showing a very uelinite meniscus end point.

Under these circumstances the luminous backing is preiei-aoiy a line of narrower wiuth than tile liquid, the line having non-luminous areas on each side thereof between it and any other luminous area sucn as an area outlining the tneriiiometer.

i Thus, when a luminous scale is positioned ad- Jacent tne thermometer stem, a thermometer is iormed asV clearly readable in dark recesses and at night as in the daylight.

Luminous areas may be created by depositing on the desired base a suitable paint, varnish, resin, gum, orsimilar vehicles having as pigment therein materials such as zinc suliide, cadmium sulncle, phosphors such as strontium sulfide, magnesium suiiioe, and the selenides 0I' various metals and alkaline eartlis. Some of these by proper treatment can be made reactive in infra red or ultra violet lights.

The invention will be more readily understood from the following description taken in connection with the drawings of a preierred embodiment thereof in which:

Figure l is a perspective View of an assembled thermometer unit; k

Figure 2 is anV elevational View of a metal base luminous insert for 'thermometers having an opaque fluid;

Figures is an enlargedfragmentary View oi a portion of the thermometer of Figure 2 Figure l is a fragmentary elevational view of av metal base luminous insert having spaced luminous background elements; and

Figure 5 is an elevational view of a metal base f having a non-luminous scale. Y

`In vthe drawings-,the numeral l0 indicates aY 3 support. Secured to the support H! by suitable means il, such as adhesive, screws, tacks, and the like, is a metal base l2.

Base i2 is oi such dimensions as to provide a luminous area I3 behind the thermometer and luminous scale and numbers I4 to one side of the stern thereof, the area between the area I Ii` and the scale i4 being non-luminous.

Support i@ is adapted with brackets l5 eXtend ing forwardly from the face thereof which secure in position a clear glass thermometer I6 of the standard mercury lled type. 1

Figure 4 illustrates a thermometer having a transparent or translucent liquid in the thermometer bulk and capillary.

There is shown herein a fragment of a base of such dimensions as to provide space for a background 2l which is made up of three spaced luminous elements, 22, 23 and 24, and a luminous scale and numbers 25, the area between elernents 22 and 23 and between 23 and 2li and between 2li and the scale being nonluminous. Thus as shown in Figure 4 a luminous stripe 23 having a width not greater than that of the clear glass thermometer stem 25 is positioned directly behind the stem (io-extending longitudinally therewith; the transparent liquid in the stem will have the meniscus thereof made visible by emission from the stripe 23; luminous stripe elements 22-24 spaced apart on said base on either side of said luminous stripe and spaced therefrom by non-luminous stripes of said base assist in delineation of the meniscus. It is immediately recognizable that such an arrangement is suitable for either a mercury filling of the glass stem as well as for the transparent liquid nlling since with mercury the luminous stripe 23 alone will indicate the meniscus.

In Figure 5 there is illustrated non-luminous indicating means positioned against a solid luminous background. The numeral 3i) indicates a support. Secured to support is a base 3i.

laseA 3i is coated over its entire surface with luminous material 32. superimposed on the luminous background is non-luminous scale and numbers 33.

Support Sii is adapted with brackets 34 which secure in position a clear glass thermometer of the 'standardl mercury filled type.

ie unit illustrated in Figures 1, 2 and 3 has a wooden base to which is secured a tin sheet of dimensions 1/2 inch wide by 3 inches long. The tin sheet is painted with luminous composi-A tion.

I employ vehicles having typical formula as follows:

Lacquer vehicle:

Parts by weight l. Pyroxylin 7 Isobutyl phthalate 3 Butyl acetate l0 Ethyl acetate 30 Butanol l0 Ethanol 35 2. Cellulose acetate 150 Glyceryl phthalate 160 Dichlorethylene 600 Methanol 200v Methylene glycol 100 Cellosolve acetate? 100 Varnish vehicle:

3. Ester gum lbs 100 China-wood oil gal 42 Heat to 520` F.

Varnish vehicle:

Parts. by weight Linseed oil gal 8 VMP Naphtha gal 60 In making'a luminous paint, the vehicle may be compounded as follows:Y

Luminous paint:

Parts by weight 4. White- Luminous cadmium sulfide 20 Zinc oxide l0 Barium sulfate 10 Vehicle l 3) 5. Yellow- VLuminous cadmium sulde 20 Barium sulfate 5 Barium chromate '4 Vehicle 2 25 6. Green- Luminous cadmium sulfide 20 Barium sulfate 5 Ultramarine blue 3 Cobalt blue 3 Varnish Vehicle 3 30 It will be understood that this invention is susceptible to modification in order to adopt it to different usages and conditions and, accordingly, it isk desired to comprehend such modifications within this invention as may fall within the scope oi" the appended claims.

I claim:

i. A thermometer assembly having tempera'- ture indicating indicia readable in the dark coinprising: a fiat non-luminous base, a clear glass thermometer stem lcarried by said base, said base having a luminous stripe thereon directly behind said stem, said stripe having a width not greater than the cross section of said stem and being longitudinally fao-extensive therewith, a pair of spaced luminous stripe, elements on said base on either side of said luminous stripe and spaced therefrom by non-luminous stripes or" said base, a transparent liquid filling said thermometer stem, and luminous indicia and markings on a side of one of said` stripe elements remote from said stem.

2. A thermometer assembly having temperature indicating indicia readable in the dark comprising: a iiat non-luminous base, a clear glass thermometer stem carried by said base, a transparent liquid llingsaid thermometer stem, said base having a luminous area thereon directly behind said stem, said rarea having a width not greater than the cross-section of said stem and being longitudinally oo-extensive therewith, a pair of spaced luminous stripe elements on said base oneither side of said stem and spaced therefrom by non-luminous stripes of said base, and luminous indicia and markings on a side of one of saidl stripe elements remote from said MALVERN J. nLEn.

References Cited in the iile of this patent UNITED STATES PATENTS Date 

